Just a quick one really. In task manager on windows 7 on the performance tab there is a section called "Physical memory" In this section there are 4 values:

Total

Cached

Available

Free

I have tried reading from the Microsoft website but it doesnt make much sense. Basically a quick explanation of each would be handy and also what happens if "Free" goes to 0? Is that normal? if not how do you fix it and what can cause it?

If the Free starts to reach a really low number and eventually go to zero, would the machine start to freeze or become sluggish? From the explanation above, even if free is low but available is 1000 the machine should still run OK?

Reaching zero is pretty darn rare. I've seen old desktops running SQL Server with only 1GB and never went to zero. It was atrociously slow, however.

1,000MB free is plenty in most circumstances. But, context is everything. Some applications use more during certain operations and if you're not watching the task manager at those times, you wouldn't know it was happening.

But, in general, if you have 1,000MB free and you're experiencing a significant slowdown, it may not be related to RAM at all. A quick scan of MalwareBytes and CCleaner will rule out the majority of possible culprits. For the rest, I'd use Resource Monitor(within task manager) to see what else is going on. Are you getting a ton of read/writes from one process?

Or, one sure fire way to tell if it is indeed RAM is to put more in and see if the problem goes away.

I have never seen RAM at 0, but I have seen it close. What is the size of your page file? Generally, RAM usage will hit a certain point, then paging gets heavier. One thing you can do is add a second HDD, and switch the page file over to it, and the program files, and then the system will hum like a champ, even if it has lower RAM. Just putting the page file on a different spindle, makes it a lot faster. Also, you can put in a USB key, and use it for ReadyBoost. i have even used an SD card for ReadyBoost.

Screenshot of the task manager in question. As you can see free is 0 but avilable is 1755!

Its a HP elitebook with an i7 processor, 4GB ram (but a 32bit OS)

Laptop has sql installed, word, outlook etc as well as some in house software.

Thanks for your contributions, it is much appreciated!

SQL probably has a lot to do with it depending on which version and what it's being used for. I recommend clicking on Resource Monitor, clicking on the memory section and looking at the "Private" and "Shareable" columns. It's probably going to be SQL using a large portion, but it could be something else as well. Sort from largest to smallest and post another screen shot for us if you're having trouble deciphering what you're seeing.

Your Physical memory is showing 42% (bottom right of the snapshot). Jst guessing I would say it is showing 0 available because it is holding in reserve. I have seen a similar issue in Exchange. I don't think you have anything to worry about. It may have something to do with the fact you are running a 32 bit OS on an i7 processsor platform. Also, it could have something to do with shared memory with the vidoe card. What Graphics card are you using. I have seen some laptops that use shared memory, and that can cause this exact scenario. You can't see the extra memory used by a process, because it isn't a process using it, but a hardware resource.

In summary, here is what each term includes ('Used' is memory in use, which is given in GB in the visual "Memory" display in Task Manager. These terms are the ones with values provided in Task Manager. See link above for description of each term.)...

Total = Used, Free, Zeroed, Standby, and Modified

Cached = Zeroed, Standby, and Modified

Available = Free, Zeroed, and Standby

Free = Free

In case anyone is interested, I reworked some of the descriptions to define some of the terms as equations. Keep in mind that Used is given in GBs or % and converting to MBs won't give a completely accurate value (just an approximate), so the calculations will most likely not be exact.